I think it's more accurate to say that China and the US each need one another. No one "wins" a trade war. Rather, everyone loses. The question then is who loses more? I suppose it depends on what you want to measure.
I think that our present trade relationship with China could be more balanced. I don't really blame China for that. Up to this point, we've been willing to allow them to manipulate their currency and protect certain segments of their economy without having to account for it. Sure, in the past, we complained about it, but ultimately we didn't do anything, so a reasonable person would say that the US didn't "really" care. Just felt the need to make some noise for political cover.
Now Trump is saying bullshit, it's not OK, and he's willing to turn over a few tables in the process to show that he really means it. If China honestly believes that Trump is willing to make it hurt for China, China will take a closer look at what it can do to appease the US and keep the lucrative trade relationship going. If they don't believe Trump will do anything, then they'll do what they did with Obama (basically ignore him).
I once heard someone say that in any negotiation, in order for the other side to really negotiate in good faith, that opposing side must truly believe that you're willing to walk away with nothing and scrap the whole thing. If they don't believe it, you'll just get window dressing concessions that aren't substantively meaningful.
I'm one of the first people to say that Trump is a stinker and I don't like his style. But in my opinion he's got a better read on his opponents than Obama ever did. And I think that all of Trump's antics make it really hard for the Chinese, and Iranians, and North Koreans to know what they're dealing with. In my view, that's a good thing, and ultimately can help us make genuine progress in each of these areas.